As newer devices emerge in data communication technology, more and more functionalities are introduced in them. The new functionalities may require additional fields in data packets or frames communicated between these devices for some of these functionalities. By including the optional information in the modified frames in a backward compatible way, older devices are still able to receive and decode the frames even if they do not receive and decode the optional information. In some systems, hierarchical modulation schemes can be used to provide some form of backward compatibility.